Crystal structures of 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]-N-(2,4-di-methyl-phen-yl)acetamide and 2-[(4,6-di-amino-pyrimidin-2-yl)sulfan-yl]-N-(3-meth-oxy-phen-yl)acetamide

In the title compounds, C14H17N5OS (I) and C13H15N5O2S (II), the dihedral angle between the pyrimidine and benzene rings is 58.64 (8)° in (I) and 78.33 (9)° in (II). In both compounds, there is an intra-molecular C-H⋯O hydrogen bond, and in (II) there is also an intra-molecular N-H⋯N hydrogen bond present. In the crystals of both compounds, a pair of N-H⋯N hydrogen bonds links the individual mol-ecules to form inversion dimers with R22(8) ring motifs. In (I), the dimers are linked by N-H⋯O and C-H⋯O hydrogen bonds, enclosing R21(14), R21(11) and R21(7) ring motifs, forming layers parallel to the (100) plane. There is also an N-H⋯π inter-action present within the layer. In (II), the inversion dimers are linked by N-H⋯O hydrogen bonds enclosing an R44(18) ring motif. The presence of N-H⋯O and C-H⋯O hydrogen bonds generate an R21(6) ring motif. The combination of these various hydrogen bonds results in the formation of layers parallel to the (1-11) plane.

Ethyl (4-benzyloxyphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate and a redetermination of ethyl (4RS)-4-(4-methoxyphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate, as its 0.105-hydrate, both at 200 K: subtly different hydrogen-bonded ribbons

Two sulfanylidene-1,2,3,4-tetrahydropyrimidine derivatives have been synthesized using acid-catalysed cyclocondensation reactions between thiourea, ethyl 3-oxobutanoate and substituted benzaldehydes. In each of ethyl (4RS)-4-(4-benzyloxyphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate, C21H22N2O3S, (I), where Z' = 2, and ethyl (4RS)-4-(4-methoxyphenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate 0.105-hydrate, C15H18N2O3S·0.105H2O, (II), the reduced pyrimidine ring adopts a conformation intermediate between the boat, screw-boat and twist-boat forms. In (I) and (II), a combination of N-H...O and N-H...S hydrogen bonds links the organic molecules into ribbons containing alternating R2(2)(8) and R4(4)(20) rings. In (I), the ribbon contains three types of ring, viz. two different R2(2)(8) rings which are both centrosymmetric and R4(4)(20) rings which are not centrosymmetric. In (II), the ribbon contains two types of ring, both of which are centrosymmetric. In compound (II), the ribbons enclose continuous channels which run along the twofold rotation axes in the space group C2/c, and the partial-occupancy water molecules lie within these channels. Structural comparisons are made with a number of related compounds.

Three-dimensional hydrogen-bonded assembly in 2,2′-disulfanylidene-5,5′-biimidazolidinylidene-4,4′-dione–dimethylformamide–water (3/2/4)

The title compound, 3C6H4N4O2S2·2C3H7NO·4H2O, comprises three 2,2′-disulfanylidene-5,5′-biimidazolidinylidene-4,4′-dione molecules, two dimethylformamide molecules and four water molecules arranged around a crystallographic inversion centre. The non-H atoms within the 5,5′-biimidazolidinylidene molecule are coplanar and these molecules aggregate through N—H...S hydrogen-bonding interactions with cyclic motifs [graph setR22(8)], giving two-dimensional ribbon structures which are close to being parallel. The two independent water molecules associate to form centrosymmetric cyclic hydrogen-bonded (H2O)4tetrameric units [graph setR44(8)]. The ribbon structures extend along theaaxis and are linked through the water tetramers and the dimethylformamide molecules by a combination of two- and three-centre hydrogen bonds, giving an overall three-dimensional structure.

One-pot synthesis of acenaphtho[1,2-b]pyrroles in the presence of supported ionic liquid catalyst

Eleven new 8-[(alkyl or aryl)amino]-9-(alkyl or aryl)acenaphtho[1,2-b]pyrroles were synthesized by one-pot reaction of (acenaphthylen-1-yloxy)trimethylsilane, alkyl or aryl aldehyde, ammonium acetate, and aryl or alkyl isocyanide in refluxing DMF.

Synthesis, characterization and biological evaluation of dihydropyrimidine derivatives

A series of dihydropyrimidines containing quinoline were prepared under conventional heating and microwave irradiation. The structures of newly synthesized compounds were established based on analytical and spectral studies. Further these compounds were evaluated for their antioxidant, antifungal and antibacterial activities. Most of the compounds showed moderate to good activity when compared with standard.

Ethyl 4-(4-cyano-phen-yl)-6-methyl-2-thioxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

The asymmetric unit of the title compound, C(15)H(15)N(3)O(2)S, contains two independent mol-ecules corresponding to the R and S enanti-omers. The dihydro-pyrimidinone rings adopt a flattened boat conformation. One of the ethyl groups is disordered over two orientations with occupancy factors of 0.700 (7) and 0.300 (7). In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O hydrogen-bonding inter-actions into one-dimensional chains along the c-axis direction. The chains are further connected by N-H⋯S hydrogen bonds, forming a three-dimensional network.

Ethyl 4-[3,5-bis-(trifluoro-meth-yl)phen-yl]-6-methyl-2-oxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

In the title compound, C₁₆H₁₄F₆N₂O₃, the dihydro­pyrimid­in­one ring adopts an envelope conformation. In the crystal, mol­ecules are linked by N—H⋯O and C—H⋯O hydrogen bonds into a ribbon-like structure along the b axis. In the ribbon, a pair of bifurcated acceptor N—H⋯O and C—H⋯O bonds generate an R₂¹(6) ring motif. Adjacent ribbons are linked via C—H⋯F hydrogen bonds.

Ethyl 4-(2,4-difluoro-phen-yl)-6-methyl-2-oxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

In the title compound, C₁₄H₁₄F₂N₂O₃, the dihydro­pyrimidin­one ring adopts a flattened boat conformation. The difluoro­phenyl group is disordered over two orientations with occupancies of 0.544 (3) and 0.456 (3). The methoxy­carbonyl group is disordered over two positions with occupancies of 0.580 (8) and 0.420 (8). In the crystal, mol­ecules are linked into centrosymmetric dimers by paired N—H⋯O hydrogen bonds and the dimers are linked into a ribbon-like structure along [100] by further N—H⋯O hydrogen bonds.

Ethyl 4-(2,4-difluoro-phen-yl)-6-methyl-1-phenyl-2-thioxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

The asymmetric unit of the title compound, C₂₀H₁₈F₂N₂O₂S, contains four independent mol­ecules, two of which are paired into a dimer by way of two N—H⋯S hydrogen bonds. The other two independent mol­ecules are paired into two centrosymmetric dimers via pairs of inter­molecular N—H⋯S hydrogen bonds. In one mol­ecule, the carboxyl­ate O atoms, methyl­ene and methyl groups attached to the benzene ring are disordered between two positions in a 0.908 (3):0.092 (3) ratio. In two of the independent mol­ecules, the F and H atoms of the diflourophenyl ring are flip-flop disordered (i.e. by 180° about the C—C bond axis linking the ring to the rest of the molecule) in a 3:2 ratio. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds.